Light emitting diode (LED) luminaires have proven advantageous over traditional and conventional lighting device by providing comparable illumination level outputs at significantly lower power consumption. LED lighting units are designed for both indoor and outdoor lighting purposes. To increase the overall lumens output, a plurality of LED light engines can be placed into a single luminaire unit and at close proximity to each other. This placement can lead to over-heating of the LED wafers and presents a challenge in maintain a suitable operable temperature.
Conventional LED lamps can include a cylindrical enclosure functioning as a heatsink and a plurality of LEDs mounted on an outer wall of the enclosure. The LEDs are arranged in a plurality of lines along a lateral side of the enclosure and around the enclosure. The enclosure can be open at one end with an air-port, or chimney, so that heat generated by the LEDs is dispersed to external air flow via convection.
In some units, the enclosure can be close-ended with heatsinks mounted (or integrally formed) on an exterior surface to reduce the internal temperature of the enclosure. Using traditional external heatsink fins may compromise the aesthetics of the fixture. These external heatsinks, typically with ridges and/or fins on an external surface, may develop dirt and water deposits that lead to reduction in thermal cooling properties and a commensurate increase in the LED failure rate.
Other conventional attempts to maintain a suitable interior operating temperature include heatsinks internal to the LED housing's enclosure. The fins of these heatsinks do not contact the housing's surface itself, which greatly reduces their thermal cooling performance. The heat radiated by these heatsinks increases the ambient temperature within the housing. To overcome this drawback, the enclosure is made large enough to obtain a sufficient heat dissipating area, making the LED luminaire itself inordinately large, heavy and bulky.